1. Field of the Invention
The invention relates to a fuel injection system for an internal combustion engine.
2. Description of Related Art
In order to improve exhaust properties, it is desirable to allow micro injection by decreasing the minimum injection amount per injection and realize a precise fuel injection control. However, as described in Japanese Patent Application Publication No. 2013-245576, an injection amount irregularity that is attributable to a bounce operation which is caused when a needle valve of an injector is fully open is likely to arise when the energizing time for the injector is shortened so as to decrease the injection amount per injection.
In contrast, the micro injection can be realized without causing the bounce operation when partial lift injection, during which the needle valve does not reach a fully-open state, is executed as described in Japanese Patent Application Publication No. 2013-104326.